Maliks Muwatta Book 037, Hadith Number 006A.

Section : Effeminate Men and Custody of Children.

Malik related to me that Yahya ibn Said said that he heard al-Qasim ibn Muhammad say, "A woman of the Ansar was married to Umar ibn al-Khattab. She bore Asim ibn Umar to him, and then he separated from her. Umar came to Quba and found his son Asim playing in the courtyard of the mosque. He took him by the arm and placed him before him on his mount. The grandmother of the child saw him and argued with Umar about the child so they went to Abu Bakr as-Siddiq. Umar said, 'My son.' The woman said, 'My son.' Abu Bakr said, 'Do not interfere between a child and its mother.' Umar did not repeat his words."

Yahya said that he heard Malik say, "This is what I would have done in that situation."